Reciprocating finishing apparatus

ABSTRACT

A FINISHING TOOL POLISHES SUCCESSIVE ANGULAR SECTIONS OF THE BOTTOM OF A ROTATING CONTAINER BY RECIPROCATING BETWEEN A CENTRAL POSITION AND OUTER POSITIONS ENGAGING THE SIDE WALL OF THE CONTAINER. WHEN THE OUTWARDLY MOVING TOOL TOUCHES THE SIDE WALL, IT IS RESILIENTLY DISPLACED AND   ACTUATES A CONTROL SWITCH CAUSING REVERSAL OF THE MOVEMENT SO THAT THE TOOL MOVES AWAY FROM THE SIDE WALL.

Oct. 12, 1-971 F. STOY 3, 1

RECIPROCATING FINISHING APPARATUS Filed March 5, 1970 2 Shaets-Sheet 1 INVENTOR BY M/u/ 1' A ATTORNEY Oct. 12, 1971 F. STOY 3,611,642

RECIPROCATING FINISHING APPARATUS Filed March 3, 1970 2 Sheets-Sheet 8 INVENTOR Flaw); 7

BY 41.14011 C ATTORNEY 3,611,642, Patented Oct. 12, 1971 3,611,642 RECIPROCATING FINISHING APPARATUS Franz Stoy, Grafenberg, Germany, assignor to Metabowerke KG Class, Ranch 8; Schnizler, Nurtingen, Germany Filed Mar. 3, 1970, Ser. No. 15,984 Claims priority, application Germany, Mar. 4, 1969, JP 19 833.9 Int. Cl. 32% 7/00 Ufi. C]. 51-55 Claims ABSTRACT OF THE DICLOURE A finishing tool polishes successive angular sections of the bottom of a rotating container by reciprocating between a central position and outer positions engaging the side wall of the container. When the outwardly moving tool touches the side wall, it is resiliently displaced and actuates a control switch causing reversal of the movement so that the tool moves away from the side wall.

MWWWWW BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION It is one object of the invention to provide a finishing apparatus, and more particularly a polishing apparatus for automatically polishing the bottom surface, and the lateral surface of the side wall of a container without requiring manual operation.

Another object of the invention is to provide a finishing apparatus for polishing the inner surface of a sink, tub, or the like without any damage to the workpiece.

Another object of the invention is to provide a polishing apparatus of simple construction which can be manufactured at low cost, and is sturdy and not easily damaged.

Another object of the invention is to provide a finishing apparatus for a container having a bottom wall and a side wall which has a tool reciprocating along the bottom of the container, and automatically reversing its direction of movement when touching the side wall of the container.

With these objects in view, one embodiment of the invention comprises a carrier means, preferably including a vertical movable carriage, and being reciprocable parallel to the bottom of the workpiece between two positions, a tool drive unit including a drive shaft and a tool carried by the drive shaft and normally abutting the bottom of the workpiece due to the action of gravity; mounting means, preferably including a pivot, for mounting the tool drive unit on the carrier means, and more particularly on the carriage, for movement between a normal position and a displaced position so that the tool drive unit moves to the displaced position when the tool abuts the side Wall in one position of the carrier means; and control means, preferably including switches, controlling motor means by which the carrier is horizontally reciprocated, and including a control switch engaged and actuated by the tool drive unit in the displaced position and connected with said motor means for causing movement of the carrier means to the other position of the same whereby the tool drive unit is moved away from the side wall.

A spring biases the tool drive unit to its normal position, and is resiliently compressed when the tool engages the side wall and is turned about the pivot means to the displaced position.

When the workpiece is rotated about a vertical axis, and the tool drive unit reciprocated in horizontal direction, succcessive angular sections of the bottom of the workpiece are polished, while the tool moves from a substantially central position to outer positions touching the side wall which causes reversing of the direction of reciprocation of the carrier with the tool.

As noted above, the tool drive unit is preferably pivotally mounted on a carriage which is movable in vertical direction so that the force of gravity urges the tool drive unit downward until the tool rests on the bottom of the workpiece. In the lower working position, a portion of the carriage rests on an adjustable pressure means so that less than the full weight of the tool drive unit and carriage act on the bottom of the workpiece. A fluid operated motor is provided for raising the tool drive unit and carriage, and is connected with the carrage in such a way that relative movement between the carriage and tool drive unit and the stationary supporting means of the fluid operated motor is possible.

In the preferred embodiment of the invention, the drive shaft of the tool drive unit is mounted on a carrier arm which turns about a vertical axis parallel to the bottom of the workpiece. It is advantageous to place the carriage for movement in a plane which is parallel to a control plane passing through a line tangential to the circumference of the tool and passing through the axis of the carrier arm. Furthermore, it is advantageous that the pivot axis about which the tool drive unit turns, is also parallel to this line. It follows, that the carrier support on which the carriage is mounted for movement in vertical direction, is connected at an obtuse angle with the carrier arm and that the drive shaft of the tool can swing perpendicularly to the above-mentioned line about the pivot.

In order to adjust the angle at which the end face of a polishing tool is inclined to the bottom, turnable connecting means connect the carrier support of the carriage with the carrier arm, and have an axis parallel to the abovementioned line.

The two end positions of the carrier arm are determined by control switches one of which is actuated by the tool drive unit, and the other of which is actuated by the carrier arm.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view illustrating an apparatus of the invention;

FIG. 2 is an elevation, partially in section along the line II-II in FIG. 1;

FIG. 3 is a cross-sectional view taken on line IIIIII in FIG. 2;

FIG. 4 is a fragmentary schematic plan view illustrating the relative movement between the Wonkpiece and the tool during polishing of the bottom of the workpiece; and

FIG. 5 is a fragmentary schematic plan view illustrating the relative positions between the workpiece and the tool during polishing of the side wall of the workpiece.

3 DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 2, a rotatable support 36 supports the workpiece 25 which has a bottom wall 24 and an annular side wall 37. A tool 4 is mounted on a drive shaft 1 which passes through a bearing tube 2 on whose upper end, an electric motor 3 is mounted for rotating drive shaft 1 with tool 4. Bearing tube 2, drive shaft 1 with tool 4. and motor 3 form a tool drive unit which is mounted on a pivot means 5 which is secured to the upper end of the bearing tube 2 in the proximity of motor 3. Pivot means 5 has a horizontal pin 6 so that the tool drive unit can swing between the normal position shown in solid lines, and a displaced position shown in chain lines in FIG. 2.

Pivot means 5 is mounted for turning movement in a member 7 which is fixedly secured to a carriage 8 having rollers 9, which run along rails 11 and 12 which are channel-shaped, and since rollers 9 and 10 have transverse axes, carriage 8 is reliably guided by rails 11 and 12 for vertical movement along an accurately defined path.

Rails 11 and 12 are secured to a carrier support which is substantially vertical in the operative position. Carriage 8 with the tool drive unit is urged by gravity to move downward until an adjustable abutment 23 on carriage 8, abuts a corresponding cooperating abutment on a variable pressure means 22 whose hydraulic pressure is adjusted so that only a desired part of the weight of carriage 8 with the tool drive unit rests on bottom 24 of workpiece 25.

Carriage 8 has a coupling projection located in the slot 17 of a member 16 which is connected with the piston rod of a fluid operated motor 14 whose cylinder is mounted on a bracket of carrier support 11. When tool 4 rests on the bottom 24 of workpiece 25, projection 18 is located at the center of slot 17, so that motor 14 does not influence the pressure of tool 4 on bottom 24. When it is desired to raise the tool drive unit, motor 14 is operated so that member 15 rises to a position in which the lower end of slot 13 abuts projection 18 whereby further upward movement of member 16 causes raising of the tool drive unit to the higher position shown in solid lines in FIG. 2.

A U-shaped member 19 is fixedly secured to carriage 8 and partly surrounds the bearing tube 2 of the tool drive unit, permitting angular displacement of the same about pivot 6 between the normal vertical position and the angularly displaced position shown in chain lines. A compression spring 20 abuts the yoke of the U-shaped member 19, and also the bearing tube 2, so that the tool drive unit is biased toward its normal position, and compresses spring 20 when moving to the angularly displaced position shown in chain lines. A carrier arm 26 is mounted by means of a pivot 28 on a stationary support 29 which also carries the cylinder of a hydraulic motor 30 whose movable member is connected with carrier arm 26 so that the same can be angularly displaced between two end positions. In the end position shown in FIG. 1, an abutment on carrier arm 26 engages the limit switch which causes reversal of the movement of carrier arm 26 by reversing fluid operated motor 30.

The free end of carrier arm 26 carries a connecting flange 32 which is connected by an adjustable spindle 33 with a connecting flange 27 secured to carrier support 13. A pin and slot connection, best seen in FIG. 2 between the connecting flanges 32 and 27 permits the turning of carrier support 13 with rails 11 and carriage 8 about a horizontal axis 34 which is parallel to the imaginary line '31 passing through the center of the pivot shaft 28, and extending tangentially to the periphery of the tool 4, as best seen in FIG. 1. The position of the connecting flanges 32, 27 is selected so that carrier arm 26 defines an obtuse angle with the plane of carrier support 13 and with the axis 34 so that the carriage 8 runs up and down in a plane which is parallel to a plane through the imaginary line 31. The axis of pivot shaft 6, about which tube 2 and the tool drive unit tilt, is also parallel to line 31 so that the tool drive unit with shaft 1 and polishing tool 4 can be angularly displaced in a direction perpendicular to the imaginary line 31. Flange 27 with carrier support 13 can be angularly displaced by operation of adjusting spindles 33 so that the end face of the polishing tool 4 is slanted at a predetermined angle to the bottom 24 of workpiece 25. A limit switch 21 on the U-shaped member 19, controls fluid operated motor 30 to reverse the same when limit switch 21 is engaged by tube 2 in the angularly displaced position of the tool drive unit shown in chain lines in FIG. 2. This reversal is carried out in the position of carrier arm 26 shown in chain lines in FIG. 1 and causes movement of the carrier means .26, 13, 11, 8 and 19 to the position shOWn in solid lines in FIG. 1.

In order to polish, or otherwise treat the bottom 24 of a container 25 having a side wall 37, workpiece 25 is secured to a rotating support. Carrier arm 26 is placed in the position shown in solid lines in FIG. 1 so that tool 4 is slightly off center to the center of the bottom 24, as best seen in FIG. 4, and carriage 8 with the tool drive unit is permitted to move downward by downward movement of the movable member 15 of fluid operated motor 14 until the end face of tool 4 abuts the surface of bottom 24 with the pressure determined by pressure means 22 on which the abutment 23 of the tool drive unit abuts. Since in the position shown in solid lines in FIG. 1, limit switch 35 is actuated, fluid operated motor 30 moves carrier means 26, 32, 27, 13, 11, 10, 19 outward toward the angular position shown in chain lines in FIG. 1. This movement is continued until the tool 4 is stopped by a side wall 37 of workpiece 25 which causes angular displacement and tilting of tube 2 with the tool drive unit about the pivot means 5, 6 against the action of spring 20 which is compressed. The position 4a of tool 4 shown in FIG. 2 is not the actual position at this moment, and tool 4 is in the position 411, while the other parts of the apparatus supported by carrier arm 26 move out of the position shown in solid lines in FIG. 2.

When the tool drive unit is tilted far enough, tube 2 operates limit switch 21 so that hydraulic motor 30 is reversed, and moves the carrier means with arm 26 back toward the center of the bottom 24. Since the workpiece 25 turns simultaneously, a different angular section is covered during each reciprocating movement of the tool with carrier arm 26, which is schematically shown in FIG. 4 in which the workpiece 25 is assumed to be stationary, and the apparatus is assumed to turn for explanatory purposes.

Due to the angular displacement of the tool drive unit upon engagement of tool 4 with the side wall 37, no hard blow or great pressure is exerted on side wall 37. Spring 20 resiliently yields until limit switch 21 is actuated. However, the reversal of hydraulic motor 30 immediately takes place upon touching of tool 4 in the position 4b on the side wall 37.

Upon movement of the carrier means with carrier arm 26 toward the position shown in solid lines in FIG. 1, and out of the position shown in chain lines, the spring 20 returns the tool drive unit from the displaced position back to the normal position shown in solid lines in FIG. 2, whereupon further movement of carrier arm 26 in counterclockwise direction causes separation of tool 4 from side wall 37 and movement of the tool toward the center of the bottom, resulting in a reciprocation of tool 4 in the direction of the double arrow 38, FIG. 4.

When the tool has arrived in its central position, as shown in FIG. 1 in solid lines, carrier arm 26 is again in its end position in which limit switch 35 is operated so that hydraulic motor 30 is reversed and moves carrier arm 26 in clockwise direction to the position shown in chain lines in FIG. 1. The reciprocation of carrier arm 26 about shaft 28 can take place at comparatively high frequency while workpiece 25 rotates in clockwise direction as indicated by the arrow 39. For polishing the side wall 37, the oscillatory reciprocation of carrier arm 26 is interrupted, and hydraulic motor 30 is set to a condition continuously urging carrier arm 26 to move toward the position shown in chain lines in FIG. 1 so that the tool 4 is slightly tilted against the action of spring 20 while abutting the side wall 37 in the position 4b shown in FIG. 2. As shown in FIG. 5, tool 4 moves along the inner surface of side wall 37 of the rotating workpiece 25, which is schematically indicated in FIG. 5 for a condition in which the apparatus would rotate, and the workpiece 25 would be stopped.

When the lowest circumferential section of the side wall 37 has been polished by tool 4, the tool drive unit is raised together with carriage 8 by operation of hydraulic motor 14 while the end of slot 17 engages the projection 18, as shown in FIG. 2. The tool 4 is thus placed in a higher position to circumferentially move along the next higher layer of workpiece 25, and this is continued until the entire height of side Wall 37 has been treated by the tool. The height of each vertical retracting movement corresponds to the height of the cylindrical portion of the workpiece 4 in axial direction.

The apparatus of the invention permits a completely automatic finishing of the inner surface of a container, and while the invention has been described with reference to a polishing tool, it will be understood that a grinding tool, or any other suitable tool may be used for the purpose of the invention.

The apparatus of the invention permits completely uniform treatment of the entire inner surface of the workpiece, without causing any damage to the workpiece, par ticularly due to the resilient mounting of the tool drive unit.

It will be understood that each of the elements desribed above, or two or more together, may also find a useful application in other types of finishing apparatus for containers differing from the types described above.

While the invention has been illustrated and described as embodied in a polishing apparatus for automatically polishing the bottom wall and side wall of a container by a resiliently mounted reciprocating tool, it is not intended to be limited to the details shown, since various modification and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. Reciprocating finishing apparatus for a workpiece having a bottom and a side wall, comprising first supporting means for supporting said workpiece; second supporting means; carrier means mounted on said second supporting means for reciprocating movement parallel to said first supporting means between two positions; motor means for moving said carrier means between said two positions; a tool drive unit including a drive shaft, and a tool carried by said drive shaft and adapted to abut said bottom of said workpiece on said first supporting means; mounting means for mounting said tool drive unit on said carrier means for movement between a normal position and a displaced position so that said tool drive unit moves to said displaced position when said tool abuts said side Wall in one of said positions of said carrier means; and control means for said motor means including a control element mounted on said carrier means engaged and actuated by said tool drive unit in said displaced position and connected with said motor means for causing movement of said carrier means to the other position of the same whereby said tool drive unit is moved away from said side wall.

2. Apparatus as claimed in claim 1 wherein said mounting means includes bearing means for said drive shaft, and pivot means on said carrier means supporting said bearing means for angular movement with said tool drive unit between said normal and displaced positions.

3. Apparatus as claimed in claim 2 wherein said bearing means is a tube in which said drive shaft is located; wherein said tool drive unit includes a drive motor mounted on one end of said tube; wherein said drive shaft has an end portion projecting from the other end of said tube and carrying said tool; and wherein said pivot means is located adjacent said one end of said tube in the proximity of said drive motor.

4. Apparatus as claimed in claim 1 wherein said mounting means include biassing means mounted on said carrier means and urging said tool drive unit toward said normal position so that said biassing means yields when said tool engages said side wall, and places said tool drive unit in said normal position before said carrier means arrives in said other position thereof.

5. Apparatus as claimed in claim 1 wherein said carrier means includes carrier arm mounted on said second supporting means for angular reciprocating between said two positions and about a vertical axis, and a carrier support means at the end of said carrier arm supporting said mounting means; and wherein said first supporting means supports said workpiece in a position in which said bottom is horizontal so that said tool moves parallel to and along said bottom of said workpiece until engaging said side wall.

6. Apparatus as claimed in claim 5 wherein said carrier means includes means connecting said carrier arm with said carrier support means for angular movement so that the angular position of said tool drive unit and thereby the angle between said tool and said bottom of said workpiece can be adjusted.

7. Apparatus as claimed in claim 1 wherein said control means includes an other control element actuated by said carrier means in said other position of the same and connected to said motor means for causing movement of said carrier means from said other position of said one position.

8. Apparatus as claimed in claim 7 wherein said second supporting means includes a support supporting said carrier means for angular movement between said positions of the same; wherein said other control element is mounted on said support; and wherein said motor means includes a fluid operated motor mounted on said support and having a movable part connected with said carrier means for angularly reciprocating the same under the control of said control elements of said control means.

9. Apparatus as claimed in claim ll wherein said first and second supporting means are mounted for relative rotation about a vertical axis; wherein said first supporting means support said workpiece in a position in which said bottom is horizontal; wherein said carrier means is mounted on said second supporting means for angular movement about a vertical axis; wherein said tool drive unit is mounted on said carrier means by said mounting means for angular movement about a horizontal axis;

and wherein said drive shaft is substantially vertical in said normal position of said tool drive unit.

10. Apparatus as claimed in claim 9 wherein said first supporting means is rotatable with said workpiece about a vertical axis relative to said second supporting means and to said tool.

11. Apparatus as claimed in claim 1 wherein said carrier means include an arm mounted on said second supporting means for angular movement, a carrier support mounted on said arm and a carriage movably mounted on said carrier support; wherein said mounting means include bearing means for said drive shaft, and pivot means on said carriage supporting said bearing means for angular movement with said tool drive unit between said normal and displaced positions; and comprising a fluid operated motor mounted on said carrier support and having a movable member for causing movement of said carriage with said tool drive unit toward and away from said first supporting means and from the bottom of said workpiece.

12. Apparatus as claimed in claim 11 wherein said carrier support has rail means extending in vertical direction; and wherein said carriage has roller means running on said rail means and including first and second rollers having transverse horizontal axes of rotation.

13. Apparatus as claimed in claim 11 wherein said bearing means is a tube surrounding a portion of said drive shaft; wherein said carriage includes a :U-shaped member through which said tube passes; wherein said mounting means include a spring abutting said U-shaped member and said tube for urging the latter to a position in which said tool drive unit is in said normal positions so that said spring yields when said tool engages said side wall and places said tool drive unit in said normal position before said carrier means arrives in said other positions; and wherein said control element is mounted on said U-shaped member and is actuated by said tube in said displaced position of said tool drive unit.

14. Apparatus as claimed in claim 11 wherein said carriage is mounted on said carrier support for vertical movement and tends to move downward to a position in which said tool abuts said bottom of said workpiece due to gravity; wherein said carriage has a coupling projection; and wherein said movable member of said fluid operated motor has a coupling portion with a vertical slot in which said coupling projection is located so that said carriage can be raised by said fluid operated motor when said coupling projection abuts the lower end of said slot.

15. Apparatus as claimed in claim 14 wherein said carriage has an adjustable abutment member; and comprising variable pressure means having an abutment on which said abutment member abuts when said tool rests on said bottom of said workpiece so that the pressure of said tool on said bottom is less than the weight of said carriage, said mounting means, and said tool drive unit.

16. Apparatus as claimed in claim 11 wherein said carrier arm is mounted on said second supporting means for angular movement about a vertical axis; wherein said carrier support is mounted on said carrier arm in such an angular position that said carriage means is movable thereon in a plane which is parallel to a control plane passing through said vertical axis of said carrier arm and being tangential to the circumference of said tool; wherein said pivot means supports said bearing means and said tool drive unit for angular movement about a pivot axis parallel with said control plane; and wherein said carrier means includes means connecting said carrier arm with said carrier support for angular movement about an axis parallel with said control plane.

17. Apparatus as claimed in claim 11 wherein said motor means includes another fluid operated motor having a movable member connected with said carrier arm for moving said carrier means with said tool drive unit between said two positions of said carrier means; and wherein said control means include another control element connected with said other fluid operated motor and actuated by said carrier arm in said other position of said carrier means to cause movement of said carrier means to said one position by said other fluid operated motor.

18. Apparatus as claimed in claim 1 comprising means for moving said mounting means with said tool drive be tween a retracted position in which said tool is spaced from said bottom of said workpiece, and a bottom working position in which said tool abuts said bottom.

19. Apparatus as claimed in claim 1 wherein said control elements is a switch; wherein said control means include another control switch actuated by said carrier means in said other position and connected with said motor means for causing movement of said carrier means back to said one position whereby said tool is again moved toward said side wall.

20. Apparatus as claimed in claim 19 comprising means for rotating said first supporting means with said Workpiece so that angular sections of said bottom of said workpiece are successively treated by said tool reciprocated by said carrier means on said bottom between a central position and a plurality of outer positions engaging said side wall.

References Cited UNITED STATES PATENTS 1,171,174 2/1916 Corry 5155 2,558,300 6/1951 Knapp 5l2 2,799,974 7/1957 Andrysick et al 51-55 WILLIAM R. ARMSTRONG, Primary Examiner US. Cl. X.R. 5l-2, 3, 33 R 

